EVERYDAY SCIENCE

Detailed explanation-1: -The process begins in the central lymphoid organs when newly formed self-reactive lymphocytes first encounter their self antigen.

Detailed explanation-2: -According to our model, T cells were the first lymphocytes to acquire variable-diversity-joining-type receptors, and the thymus was the first lymphoid organ to evolve in vertebrates to deal with potentially autoreactive, somatically diversified T cell receptors.

Detailed explanation-3: -Antigens and dendritic cells (DCs) reach the draining lymph node through afferent lymphatic vessels; they must then enter the lymph node and migrate deep into it to activate T cells. Lymph nodes are enclosed in a collagen-rich capsule, which is underlined with lymphatic endothelial cells forming the subcapsular sinus.

Detailed explanation-4: -The lymph is composed of a mixture of biomolecules, including proteins, peptides, and exogenously derived antigens that reflect the state of the peripheral tissue.